Fluid disconnects in flow lines are used in various applications, including flow lines which interconnect an anhydrous ammonia bulkhead with a portable transport. The primary purpose of the disconnect is the ease of separation along this flow line, along with the ease of reconnecting the flow line to another portable transport.
While various types of disconnects are commercially available, many of these disconnects allow for a significant loss of fluid during disconnect separation. Each time the disconnect is separated, a sizeable amount of fluid escapes before the disconnect valves seal, and this escaping fluid, in addition to the fluid which is normally spaced between the closed valves of the disconnect, escapes to the atmosphere. This loss of fluid commonly is at least several hundred CCs of liquid, and the lost fluid either contaminates the soil surrounding the bulkhead station or vaporizes to contaminate the atmosphere. Other fluid disconnect systems cannot operate reliably at high fluid flow rates and/or high pressure, thereby limiting the use of the disconnect in systems where the time required to transmit fluid through the flexible flow line is at a premium.
The disadvantages of the prior art are overcome by the present invention. An improved flow emission disconnect system is hereinafter disclosed which is particularly suitable for use in a flexible flow line extending from a transport to a bulkhead. The fluid disconnect system is rated at a high flow rate and a high pressure, and most importantly the disconnect system results in a very slight loss of fluid as a result of the disconnect operation.